S-99291A480 1/2"-20 Locknuts

Key Features & Benefits at a Glance

• Superior vibration resistance through distorted thread locking technology that maintains clamp force in high-stress environments
• Enhanced corrosion protection with black-oxide steel finish for extended service life in demanding industrial conditions
• Reliable high-strength performance meeting ASTM Grade C specifications for heavy-duty applications
• Precise thread engagement with Class 2B fit ensuring consistent installation and optimal load distribution
• Industry-standard compatibility with 1/2"-20 UNF fine threads for seamless integration into existing assemblies
• Easy installation and removal using standard external hex drive tools for efficient maintenance operations
• Environmental compliance assurance with REACH and RoHS 3 certifications for global manufacturing requirements

Professional Applications & Engineering Value

This distorted thread locknut delivers exceptional engineering value in applications where vibration resistance is critical. The black-oxide steel construction provides superior corrosion protection while maintaining the ASTM Grade C strength required for heavy machinery, automotive assemblies, and industrial equipment. The top lock distorted thread design creates consistent interference that prevents loosening under dynamic loads, eliminating the need for secondary locking devices. With 1/2"-20 UNF fine threading and Class 2B thread fit, this locknut ensures precise engagement and reliable performance in high-vibration environments where standard fasteners typically fail. The external hex drive allows for straightforward installation using common tools, reducing assembly time while providing permanent vibration-resistant security.

Specification Summary & Compliance

This locknut features Class 2B thread fit per UNF standards with precise 1/2"-20 fine threading and right-hand thread direction. Manufacturing complies with ASTM Grade C strength requirements, ensuring consistent mechanical properties. The product meets REACH (EC 1907/2006) compliance for 224 SVHC substances and RoHS 3 (2015/863/EU) environmental directives. Physical dimensions include 3/4" width across flats and 7/16" height for standard tool compatibility and space-constrained applications.